Extraction pkocjss and apparatus



w. F. 'HOLZHEUER spt. 2o, 1927.

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w. F.V HQL'ZHEUER- EXTRACTION PROCESS AD APPARATUS Sept. 20, 1927.

OgnaIFle'd Serif; 28, 19.25 4 Sheets-Sheet 5 w. F. l-loLzmauER` BXTRACTION PROCESS AND APPARATUS V sept; zo; 1927.

.Drrnal Filed Sept 2g, 1925 4 Sheets-Sham;` 4

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Reissue'd sept. 2o, 1927.

UNITED -sTATES PATENT OFFICE. z

WILLIAM FREDERICK HOLZHEUER, or. HALE,- MICHIGAN.

EXTRACTION PROCESS` ANDl APVKPARATUS.

original N0.'1,5s7, e46, dared rune s, 192e, serial 110.59247, ma se'pemp'er'zs, 1925. y.'1pp1iea'c1oiifor y reissue led August 16, 1927. 'Serial No. 213,515.22.

My invention relates to an apparatus and process for the extraction orditfusion of the sugar content from saccharine bodies, such as sugarbeet cuttingsin particular.

E, In the process in use at the present time for extracting sugar from the sugar beet, the finely sliced beets, or cossettes, are loaded into a series of diffusioncells connected with each rother' thru various pipe connections to form a battery, and water `is circulated `from cell to cellalong this battery to diffuse the sugar content from the cossettesV into the water, which becomes yrich in sugar as it proceeds by circulation along the length'A ot the battery. .This water is supplied under moderate pressure at the point where it en ters the battery, the: pressure being 4produced either by gravity' or by some mef chanical mea`ns,'the vspecific. mode being immaterial. The piping between theV cells is so arranged that'the course of the water is downward thru each cell'and' upward thru the calorisators, which'are usually interposed i' in the pipe connections leading from the bottom ofone cell to the top of the next cell. l

Though the number of 'cells in the series forming the" battery, may vary, and the .slze of thesev cells may also vary lboth in height and diameter, nevertheless a typical example might be described as constituting about fourteen cells. the Adiameter of each cellV being about ten foot. s

Though the exhausted cossettesare usuallyy being dumped Vfrom onev cell, while tive foot, and the height Vabout another cellis being filled, and while still another cell is undergoing the mashing7 operation, thus accounting for a total of three cells engagedfin these special operations, nevertheless'the remaining cells', ne., fapproximatelyeleven cells, are connected'in the series circulation of' the water, which gradually becomes ,a rich above described. f f

Because of the fact that each ofthe eleven cells in this 'circulation `are loaded full with comparatively tine beet cuttings or coss'ettes, which arepaclred into the cells quite tightly,

it is obvious that the resistance to the flow Y or circulation of thefwater along thru the length of the battery, `a nd thru cell` after. cell, is quite large. andthe rate o-thisflow, which is commonly referred to as the cir-v Cumtmn, is greatly retardedl onacc'ount of sugar juice, as

. the greater the capacity orftotal daily tonnage of cossettes that can be handled with a`v given amount of this diffusion battery equipment, and since many beet sugar factories find their diffusion is the slow point in theirent-ire factory ope-ration, their efforts are naturally interested in Vany rimprovement that will speed-up the battery circulation, and thereby increase .the hourly tonnage that can be yhandled by their battery, as such increase will immediately release the additional capacity that. they have in the othermachines and stations of the factory, so thatrthe hourly tonnage or capacity of the entire factory can be increased by eXactly the amount that' the d itfusion battery capacity is increased. This overall increase ofthe total factory capacity is of utmost importance, as the investment in all the Inachinery in a beet sugar factory, even outide the diffusion battery, is exceedingly ar e.

ne obvious limitation against high rate ofl circulation. 4in 4the ordinary battery opera-ted in the usual manner, arises from the fact'that the water pressure at the point where the water ,enters the battery, can only be raisedy toa moderate amount, because if it is raised labove a certain point, its downward force or How in the first few cells 'is sogreat` as to drawithe entire charge of cossettes y in those cells downward forcibly against thel bottom :of the cells, and to pack 'these cossettes so tightly onto theibotto'm that they act more or less in the vnature of a large valve'and practically closeofil the flow or circulation completely, so that in -pl'aceof increasing the rate 'of circulation by virtue of increasing the initial'water pressure, just' the reverse resultsare obtained.

Tnorder to vhold the cossettes up and prevent them ,from 'packing so tightly onto the bottom of the cell, as just described, yvarious l I expedients, such as large quantities of chains hung transversely across .the cells at various elevations, Ltheriv,` have been `resorted to,

with a `fair degree of success, but the number of chains that can thus be hung in the cells is limited by the fact that if any excess of chains are used it becomes very difficult to load the original cossettes into the cells, and it also becomes diiiicult to dump l the spent cossettes out of the cells, and the time lost by increased Adifficulty from these causes greatly osets the benefit of increased rate of circulation. In other Words the benefit derived by using chains torsupport the cossettes Within'ther cells, so that a somewhat higher initial Water pressure'can be used in order to speedup the circulation, is' limited, and those factories Where this expedient has been increased to the limit of its usefulness, often for various reasons find themselves desirous of still further increasing their rate of battery `circulation,`but find it impossible to do this by any process or means heretofore at their disposal.

The principal' object and benefits of the arrangement and new process of operating the battery, `which I have invented,y and which I lwill hereinafter describe, is directed tow-ard effectively 'increasing theV batteryl circulation in-a very substantial manner, this increase being gained over the best rates of circulation heretofore produced. Briefly, my. new process consists in adding" to the ordinary battery operations the new step of in some Way boosting the circulation pressure' ata place intermediate vof the ends of said battery, by passing the juice orliquor thru some pressureboosting means provided for lthis purpose. Preferably this pressure boosting means consists in some sort of a pump, and one. very convenient place for locating it is in the connections where the liquor passes from one of the cells in to another of the cells in the series.. In the broader aspects of my invention, the particular arrangement and locationv of the apparatus by which the circulation pressure is thus boosted intermediate of the ends of thevv battery, is of course immaterial, and is limited Vonly by the restrictions set forth in the appended claims, but one form of ap-.. paratus forl carrying out Vmyinvention con: sists in-adding to the ordinary piping whichv connects the .various cells, anadditional series of valves, and proper headers, so that after the Water or juice has flowed approXimately thru half the cells under the force of" the initial pressureyit is brought .thru the headers to a; pressure boosting pump orv means Where its` pressure is lraised by any. desired amountn and at this boostedV lpressure passes intoffthev nextcell in the seriesandth reby the speedoff circulation tliltlfthe entiref battery isf-considerably 4increasedf f rlfhis particular form'of apparatus for-carrying ontfmy invention makes, it' pos.-

Sble; te rfllosiferely Change the? Place 11i the;

battery Where the pressure is' boosted, this being done by manipulating the. said valves so as to progressively move ahead the place Where the circulation pressure is boosted, so that this operation remains in step With the progress of the other operations progressively around the battery.` vThough this progressive changing of the place for boosting the circulating pressure, has some advantages, nevertheless, the apparatus and operation of same is a little more complicated lthan if theI special valves .and manipulation Iof same omitted, which latter would result iny leaving the pressure boosting pump or pumpscofnn-ected at a fixed place or places in the batt-ery, instead of progressively changing this place, and if this simplified form ofv apparatus for carrying out my invention is desired, it can be successfully used and installed by simply omitting the special series of valves previously referred to. If this is done, it should be noticedv hovvever that the essential feature `of my invention lis still retained, to-Wit.l the new ste-p of in some Way boosting the circulation pressure on the battery at some point `or points intermediate of the ends thereof, so that this boosted pressure assists the initial pressure in speeding up the ciri culation.

As previously indicated, should it be found that merely boosting the pressure at one point in the battery is not sufficient, my invention contemplates that the pressure can be boosted at tvvo,three or lmore points along the battery, the modification of the i ap` paratus for this purpose being fairly obvious. f' I will nonr describe one form of yapparatus foiI carrying. out my inv'ention-,fb,ut though the form wh ich I have selected for this de scription is that which enables the place for boosting the pressure to be progressively changed along the length of the battery, nevertheless it should be noticed that in accordance with the foregoing remarks this place or places for boost-ing the circulation pressure can remainhiredat definite points in the battery instead of moving progressively along same. i n

Fig. l is a top plan y'view of a battery of fourteen cells` arranged in a straight. line system; FigjQ, isa front elevation. of the same; Fig. 3, is af rear elevation thereof; Fig. 4v, is a side elevation; Fig. 5, is another side elevation but looking inA the opposite direction to'k Fig. 4t; Fig. 6, is atransverse sectional View talenon line 6-6 of Fig. l; Fig. 7,L is: a similar sectional view takenr longitudinally thru a portion of the ap-v paratus: Fig. 8 is a horizontal longitudinal sectionaly view'vron line 8 8 'of Fig'. et.

Iny the, several views of thedrawings I have, shown abattery of diffusion cells, which tolaidfin the description, varenumbered from lfto, 14' cc'insecutive'lyv',V andY v Which are arl rangedin a s'traig'ht'line', kalthough it is of lili) courseunderstood that the cells may be arranged 1n a curve, circle, rect-angle, orv 1n any otherdesired manner.- y

" the two-way valve 26, and the pipe r2O, there being one of each of these parts inthe connection leading from this Water header 17 to the topof each of ther cells. `As is best indicated in Figs. 3,- 4 and 7,'a pipe 2l leads from the lower end 'of each diffusion cell, up toa valve 22, and if desired this vertical pipe 21, can be arranged in the 'manner of a calorisator for heating the juice as it comes Y from the bottom of one cell up thru this' .pipe on its way to the next cell.

As best indicated in'Figs. 1 an'd4, a pipe 23 connects this valve 22 with a two-Way valve 24, from which the branch ypipes 24 and 25 extend, theformer being connected with allongitudinally extending headerf27, which leads to a measuring tank as hereinafter described, yand the pipe 25, best shown in Figs. 1,2 and 4'being connected with the two-Way valve 26, ofthe next` succeeding cell. j I

The header 27 is connecte'dat one end with the measuring tank 30, see Fig. 5, by means of a pipe 28 and the valve 29 'located adjacent to ythe tankfA second measuringtank 31, see Figsrl andv 4, is connected with the pipe 28 by means of a branch pipe 32, land v, a valve 33.

Another llongitudinally extending header 34best seen'in Figs. 1, 2, 4and-f5, is connected at 'each cell by'means of a pipe 34,

' valve 35, the two-Way valve 35,'and pipe 35", with the vertically rising pipe 21, previously described. 'v If 'desired a storage tank 36, seeFig. 4, for receiving sweet water can be mounted on platform` 16, nearthe Vend of the battery Where the measuring tanks 3() and 31 are located,l and this tank 36 can be connected with theadjacent end of header 34 vby means of' a p pe 37, communicatingwith the bottomvof the tan In this case a longitudinall header 39' can be disposedv above thediusion cells, see Fig. 4, andthis hea'der 39isat each cell `provided with a valve 52 which communicates through ,a branch pipe 51, with the .pipe 49 vthat' enters the upper end of each cel1. *The end'of header 39 connects with pipe 40, heater 41, andpipe 42, leading to the'k upper endfof the storage tank 36.* f if f 'f In cases where the storagetank ,36 is not -used,the'heeder 39'1an`d pipes l40,'4/1', 42 and 37 may be omitted, theirV points of connection With pipes 49 and'header 34, Figure 4, being oi course closed or sealedv by means of a proper cap or closing iang'e. .t i

- AS is nicely i nd `cate'd in Fig. 4, aided by Fig. 2, each of the vertical pipes 49 leading from'the upper ends of the respective cells, isconnected through ar valve 5() "with another longitudinally extending'header 47, which may be'described as thehigh ressure side of the boosterheader, as the en of this header is :connected -fby means of pipe 48,' heater 45, and pi e 46, with the discharge or high pressure si e of the booster pump 44,

,which is used to boostthe pressure in order L;-

to Speed. up 'the battery circulation in the manner indicatedpin a'. former part of this specification.`

The heater 45,y according as suits'the taste of the' designer. Also I have shown the power drivenpressure boosting pump` 44 asrepresented by a centrifugal pump, but any other kind of a power driven pump can of course be used, and same can be driven eiHier electrically, mecha-nically or in any other desired manner. In this connection it might rbe note'dthat the above mentioned heaters 'or' calorisators "arranged inthe pipe connections between the cells, perhapshave an'exceedingly small effeet on the pressure ofthe iiuid because of the exceedingly small expansion that results may, or. may not be used,n

from the heating effect-of the calorisators,

but obviously the pressure change due to this cause is sosmall as to be 'utterly negligible so far as practical operations arefconcerned, In Vfact itis imp ossiblezto measure or notice this Vchange ofpressure due ytothe calorisa# tors, on any'of the pressure gauges ordinarily used on-these diffusionY batteries. There$ fore this negligible and innitesimally small change of pressure due to the calorisators, is

Ventirely disregarded and isnot embraced within theterm boosting the pressure, etc., as used in this application;

The lo7 pressure -side of thepump 1 or pressure boostingl means .44is connected through pipe ,43? to the adjacent en'd of another longitudinallyr extending header 43, which `latter is connected byA means ofk pipes 43bwith the two-wayA valves `35a from which the connection leadsvthrough pipes 35b and 21 to the bottomiof veach cell.` f

' 'For'obvio'us rreasons this header 43 may be termed lthe lowpressure header ras it-is the one from'which the juiceis drawn from one 'of the cellslapproximately in the-'center of the circulation, vand'led tothe booster'pump :tory boosting'the pressure on the juice before sameis passed" back valong header 47 and injectedQinto 'the next cell following the O'ne from whicht is drawn rinto Vtheheade'r 43. `In regard tothe,l h-igh'pressurelheader 47 ,git is "of course'understood'that all of 'the valves "50, leading from vthe 'respective .'cells,

il ll excepting one, are closed, and likewise that a-ll of the valves `35 leading from the respective cells to the low pressure booster header 43, excepting one, are closed, and that in this way through the one lvalve 35a which isopen, the juice is drawn from that particular cell through the header 43 into thesuction side of the pump' where its pressure is boosted by the pump and passed back jinto the high pressure header 47 Where it "passes through the one valve 50 which is open, into the next cell in the series. As the opera-tions progress along the battery from cell to cell,the one valve 35a, and the one valve 50, which is open, is progressively changed' from cell to cell along the battery as the operations progress,` so that it is seenthat `the particular point in the battery at which this boost-ing is done progresses along the' length of the battery in keeping with the other steps in the battery operations.

If it is desired to reduce the cost of installing the particular form of pressure boosting apparatus which I have just described in detail, and still retain the ability to progressively change. or move ahead the place in thebattery'wherethe pressure is boosted, this can be done by yomitting pipes 49 and the two-Way valves from every other cell, or from everyvtwo out Of three cells-etc., which will reduce the cost of in" stallation very substantially, and the labor of manipulating the omitted valves willb'e saved and avoided. Notwithstanding the t particular omissions and simplifications just mentioned, satisfactory results will still be obtained, andthe speedl of battery circulation will be considerably increasedr above the ordinary ycirculation rate in which my invention of intermediately boosting the circulation pressure is-not used; besides the place of boosting the circulation. pressure can still be progressivelyv changed along the battery, even though therparticular simplific-ations and omissions mentioned in this paragraph are resorted to. 'v i y In .order to complete the description of the piping shown, the following remarks may be helpful. f i j If the Sweetwater tank 36, and its other connectedvparts, are used, an emergency discharged'pipe 53 maybe installed for connecting pipe 48 of the pressure boosting circuit with the upper end yof the storage. tank 36, the lconnectionthrough this pipe 53I being cut olf however by ymeans 'of a safety valve 53h, which is normally closed to prevent circulation through pipe 53, but which opens to relieve anyexcessive pressure that may for any reason'be built up in the high pressure portion of thebooster system. jA pipe may also he connected? withthe upper end ofvl storage-tank' 36,'thispipe v(5() being suitably oonnectxed so 'asto collectit sweetf waterthat; may accumulate at other-stations or places of operation in the beet sugar factory. l

Also outlet pipes 55 and 56, Figs. 4, and 5, connect the `measuring tanks 30 and 3l respectively with the 'carbonation apparatus of the sugar plant, (not shown), and these pipes are provided with valves 58 and 59.

Header 70, shown in Figs. l, 4, and 8 is an accessory pipe that is used in various ways by those accustomed to operate these diffusion batteries.

The foregoing description concludes the essential portions of the. piping and other apparatus in a diffusion battery on to which one form of my apparatus has been attached for carrying out my invention of boosting the circulation pressure at a place intermediate of the ends of the battery.

I will now describe the manner of setting the valves for some of the steps in the battery operation, it vbeing understood that these settings progress from point to point, and cell to cell along the battery as the operation continues.

Assuming that the .battery isin fullY operation and thework progressing normally, it is realized that water under an initial pressure head will be entering one. of the cells, this being the starting point in the circulation. As a matter of fact -this fresh water usually enters the cell in which the cossettes are most exhausted of .their sugar content. 0n this particular cell the valves will be set as follows: Valve 19 will be open; the twoway valve 26 will be set so as to connect valve 19vwith pipe 20, and so as to cut oft the pipe 25 rising diagonally and eventually connecting with thel bottom of the preceding cell. Obviously this will permit thev fresh waterqfrom header 17 to pass through pipe 1S, valve 19. two-way valve 26, and pip-e 2O into the cell at the top, from 'whence the` circulation proceeds downward through this cell and upward through the pipe or calorisator 21 connected to thev bottom of this cell and from this pipe 2l'the juice passes up through valve 22, branch pipe 23, two-way valve 24 and pipe 25 into the two-way valve 26 of .the next following cell. In the portion of the pipingjust mentioned, the twoway valve 35a, Fig. 4, is .closed against the branch pipe 35", valveL 22 is open, the twoway. valve 24 is open to .pipe 25, but closed to pipe 24a, and the two-way valve-26. inr the next succeeding cell is open so as to connect the circulation'from pipe 25 through pipe 20 into the next cell. From this next Cell through which the circulation is down- Ward, the juice again rises upward through thepipe v"or calorisator 21. and into the top of the next' cell in thesame; manner as just described,l thesetting of the valves being identical; In V similar manner the circulation lproceefzds from cell to cell, always being downward through each cell, and upward throu h they intervening piping to the next cell, le fresh water which was introduced into i the cel-1 having the `most exhausted vcossettes, gradually becomes richer in sugar as -it diffuses the sugar by osmosis from the cossettes into lthe juice, this enrichening of the juice proceeding cumulatively fr om cell to cell until the richest juicejafter passing i' over the last cell, Ain whichl the new and richest cossettes arey found,`leaves the battery and proceeds to the measuring tanks 30 and 31, by a settin of thevalves which will presently be descried. y i i I As previously described,Vv at alplace in the l foregoing circulation roughl midway 'along' its length, or at anyother esired' point or .Y Ypoints between the ends ofV the battery, i. e.,

between the cells where the fresh water is admitted at one end, and the rich juice is discharged to the measuring tank at the other end, the juice ispassed thru a pressure boosting pump, from which it re-enters the next cell in the circulation at a. higher pressure than it emerged at from the cell just preceding, and in View of this step or operation in the process, the speed of circulation throughout the entire battery is greatly increased, with very large benefits 'of a character that is well understood by those skilled in the operation of these diffusion batteries.

The setting of the valves on the last cell l inthe battery, where the rich juices are being led to the measuring tank 31 for ultimate discharge from the battery, are `as follows: The valve 22, Fig. 4, is open, and

e the two-way valve 24 is closed vagainst pipe 25, but open to pipe 24, so as to allow the juice to flow down through pipe 24. into header 27, vand along same into pipe 28, from open.

`which it flows either into tank 30 or 31, ac-

`Vcording as to whether the valve 29 or 33 is At this time the two-way valve 35a is of course closed against pipe 35.

The headers and parts 34, 34a, 35, 36, 3T,

l39, 40, 41, 42 and 52, all of-which have 'been previously described,can be used under the following circumstances. Assuming that a.

' cell beyond the one into which the boosted v valve 52 corresponding with and adjacent to the open valve 50, is also opened somewhat, 'so that some of the high pressure juice from the high pressure header 47, will flow through pipes 40, 4l, tank 36, pipe37hea'der 34,.pipe .34a and into the bottom ofthe pluggedcell byproperly operating the following valves corresponding to that cell.

given.

The valve 35 is opened, the two-way valve 35a 1s closed against the pipe 43h and opens valve 35 into pipe 35", from which the fluid and as soon as this plugging action is relieved, the valves are all returned to ftheir normal operating position, and the circulation and diffusion operation continues inits normal manner.

For certain other detailed steps in the operation which may at special times be desired, the various valves shown and indicated may be manipulated to produce same,

but these Vvarious details of operation have nothing to do with the pressure boosting features which constitute the principal parts of my invention, and being well understood by those skilled in battery operations, same need not be further vdescribed herein.

In conclusion I wish'to point out that the art or process of drawing the juice thru any pressure boosting means in any wayinterposed in the battery circulation at a place or places between the'ends of the battery for the purpose of boosting the circulation pressure, in order to speed up the circulation, is broadly ,new and pioneer so far as Il am aware, 'and that I broadly am the inventor thereof, and of the yvery substantial benefits both from improved diffusion efficiency and increased battery and factory capacity that may be obtained thereby.: As previously indicated this step in the process can be performed by arranging the pressure boosting apparatus in several ways different from the vone specifically and minutely described in the paragraphs just preceding, but in case the users of this invention and process desire to progressively change the place ,A in the battery where the'circulation pressure is so boosted, in order to'keep this operation in relative stepv with the other-batteryV operations, this can vbe done by installing the apparatus substantially in accordance with the detailed description which I' have just As one of the benefits derived from my boosted circulation pressure, v'and not previously mentioned, Ir callattention to the fact that thereis sufficient pressure to both draw -juice from this last cell into the measuring tanks, and also to force juice from this last'cell yup through the next cell of fresh cossettes which are being mashed. In the ordinary mode of operating a diffusion battery Without,.myboosted pressure, Ait'is f very. difiicult, or impossible, to obtain enough pressure at the end of the batteryto both draw and mash at the same time, and for arts. and industries wherever it is desired to y extract into a liquid a desired ingredient from a. substance loaded into adiffusion battery. In, the sugar industry the liquid consists ot water which gradually becomes richin sugar as it circulates along the length of the battery; the desired ingredient isfthe sugar; and the substance loaded into the diffusion battery is the beet cuttings or cossettes as hereinbefore described; but in other arts or industries the liquor, the desired ingredient, and the original substance, together with otliersubstances that may be present, may allv be diierent from those in the sugar industryfbut my invention is useful and applicable nevertheless, and I claim it in respect to those other arts and industries as well. as for the sugar industry.

Also, various modifications of my apparatus and process, in addition to those hereinbefore specifically mentioned, will Vbe aparent, but these are all included within the Eroad scope of the appendedclaims to which reference should be made for ascertaining the breadth of my invention.

I claim;

l. The process of extracting into liquor a desired, ingredient from asubstance loaded intoardiffusion battery, said process consisting of circulatingthe liquorl under an initial pressure progressivelyl through a series of cells vconstituting the battery and'containing the original substance, and boosting the circulation pressure of said liquor at a place intermediate of the ends ot' said battery by passing said liquor through a power driven pressure boosting pump provided for this purpose.

2. The process of extracting into liquor a desired ingredient from a substance loaded into a diffusion battery, said process consisting of circulating the liquor progressively through a series of cells constituting the battery and containingthe original substance, and boostingy the circulation pressure otsaid liquor at a place intermediate of the ends of said bat-teryby interposingiapower driven pressure boosting pump in the circulation at a 'place where thev liquor passes from lsignature hereto this 27th day of July, 1927.

one of the/cells into another ofthe cellsin the series.

boosting pump in the circulation at a place where the liquor passes Afrom one cell into another lcell in the series, the particular cellsV between which the power driven pressure boosting lpump is interposed being changed` progressively along the battery as the other steps in the extracting process proceed -along the battery.Y

4. An apparatus for carrying out my herein described process, consisting of a diffusion battery having a number of cells in series, said cells being connected with each other through valves and piping so that a fluid lintroduced into said series of Cells can circulate progressively from one cell to another along the battery, and means for boosting the circulation pressure of said fluid at a point along its course through the-battery, consisting of a low pressureheader connected with various-.ot said cells through separate valves, anda high pressure header also Y* connected tov various of said cells through separatevalves, said low and high pressure headers being connected to each other [through a pressure boosting means, one of said valves connecting one ot' said cells with said low pressure headerwbeing open, while one of said valves connecting another ofj said ycells with the high pressure header is open to cause. said fluid to pass from one cell through said pressure boostingmeans and back into another cell at a higher pressure.

5. The process of extracting into liquor a Vdesired, ingredient from a substance loaded into a diiusion battery, said process consistingof circulating the liquor under an initial pressure progressively through a series of cells 4constituting-the battery and containing the substance, said circulation being nor- 1 mally downward through said cells, nor- -mally boosting the circulation pressure ot said liquori at a place intermediate of the vends of-said battery by passing said liquor through a pressure boosting means, rand occasionallyusing said pressure boosting means lfor establishing a temporary counterflow upward throughone of said cells to Y relieve same-of any plug which may have WILLIAM 1 FREDERICK' HoLzHEuER. 

